| Domain | Definition | Key Concept/Application | | :--- | :--- | :--- | | | Imaginary north-south line for longitude | Prime Meridian, time zones, GPS | | Land Surveying & GIS | Reference lines for public land surveys | Principal meridians (e.g., PLSS, DLS) | | Astronomy | Great circle through celestial poles & observer's zenith | Culmination, celestial coordinates (Right Ascension) | | Astrology | Great circle for calculating the astrological chart | Midheaven (MC), House systems (e.g., Meridian System) | | Traditional Chinese Medicine | Conceptual energy pathways in the body | Acupuncture points (acupoints), qi flow |
In mapping, meridians are great circles that pass through the Earth's poles to define longitude. Core Coordinate Systems Geographic Coordinate System (GCS) meridian coordinates
"Meridian coordinates" is a phrase that bridges two fundamentally different ways of understanding space and connection. In geography, meridians provide a universal, mathematically precise grid that enables global navigation, time synchronization, and mapping—a triumph of Enlightenment science and international cooperation. In traditional Chinese medicine, meridians provide a clinically useful map of the body's surface, guiding the placement of acupuncture needles to treat disease based on millennia of empirical observation. | Domain | Definition | Key Concept/Application |